HAVANA -- Cuba apparently has finally switched on the first undersea fibre-optic cable linking it to the outside world nearly two years after its arrival, according to analysis by a company that monitors global Internet use.

In a report posted Sunday on the website of Renesys, author Doug Madory wrote that Cuba began using the ALBA-1 cable on Jan. 14.

Until now the island's Internet service has been through satellite links that are slower than hard-wired fibre-optic connections. Starting a week ago, Madory said, routing data showed significantly faster traffic to the country and the emergence of Spanish telecom Telefonica as a provider of routing service to Cuban state-run communications company ETECSA.

Routing speed is measured by how long it takes to send a data packet somewhere and receive confirmation back at the original server, akin to how submarines "ping" each other with radar to determine location.

Madory wrote that the sudden improvement in latency measurements between Cuba and four cities in the U.S., Mexico and Brazil indicates the cable is in use. But speeds have not reached levels suggesting that the cable is handling all traffic, leading him to conclude that outgoing data is still traveling via satellite.

"We believe it is likely that Telefonica's service to ETECSA is, either by design or misconfiguration, using its new cable asymmetrically (i.e., for traffic in only one direction)," Madory wrote.

Cuban government officials and Telefonica did not immediately respond to requests for comment Monday. Cuba has said in the past that it would prioritize the cable for usage deemed in the public interest and for social good.

Dial-up Internet access, essentially the only option for most Cubans who are able to go online, has continued to be slow and creaky in recent days.

Cuba is the last country in the western hemisphere to get a fiber-optic hookup and, according to Akamai Technologies Inc., has the second-lowest Internet connectivity rates in the world.

Havana says about 16 per cent of Cubans are online in some capacity, mostly through work or school, but often that's limited to email and access to an island Intranet. Just 2.9 per cent report having full Internet access, though analysts say it's probably more like 5 or 10 percent due to underreporting of black-market resale of minutes.

"While the activation of the ALBA-1 cable may be a good first step to providing ETECSA a better link to the Internet, the lack of widespread public access to Internet service throughout the island will likely continue," Madory wrote.

The $70 million cable strung from Venezuela came onshore in eastern Cuba in February 2011 and was supposed to be online as early as that summer.

But officials suddenly stopped talking about the cable amid rumors of arrests at ETECSA and the Ministry of Communications, and whispers of purported mismanagement or embezzlement involving the project.

Last May, Venezuela's minister of science and technology said the cable was operational and it was up to Cuba to decide how it wanted to use it.